Net::SMTP
Have you tried this module? I have used it many times for email and I have always had good luck with it. Something I have also noticed while playing with email from a script, is moving around the order of the Header portions, i.e. From:, To:, then Subject: and so on. I can't really explain why, but I have had a lot of luck with doing this whenever I run acrossed issues of a script not sending the correct email, or no email at all.